Unusually low surface recombination and long bulk lifetime in n-CdTe single crystals

We present a study of time-resolved photoluminescence (TRPL) measurements of n-type CdTe single crystals doped by a novel procedure. The measurements show that the surface recombination velocity of low doped n-type ${\mathrm{(n}}_0{\text{=1.5×10}}^{16}\hspace{0.17em}{\mathrm{cm}}^{\mathrm{-3}})$ samples was below 200 cm/s and the nonradiative bulk recombination time was around 180 ns. By conducting the TRPL measurements under different carrier injection levels, it was found that radiative bulk recombination was the dominant mechanism in the low doped crystals. This enabled us to obtain the bulk radiative recombination rate constant, B, which was found to be ${\text{3±0.5×10}}^{\text{−9}}\hspace{0.17em}{\mathrm{cm}}^{\mathrm{3}}{\mathrm{\hspace{0.17em}s}}^{\mathrm{-1}}.$